White light-emitting diode with high uniformity and wide angle intensity distribution

Abstract

The present invention relates to a white light-emitting diode with high uniformity and wide angle intensity distribution, and particularly relates to a color temperature tunable white light-emitting diode with high uniformity and wide angle intensity distribution. A nano-phosphor material is coated on one surface of a lampshade of the white light-emitting diode to form a white light phosphor layer for providing a stable white light with high uniformity, wide angle intensity distribution, and good illuminance. Furthermore, the color temperature of the white light-emitting diode can be adjusted by changing the ratio of compositions of white light phosphor layer.

Description

CROSS REFERENCE[0001]This application claims priority from Taiwan Patent Application No. 102127683, filed Aug. 1, 2013, the content of which are hereby incorporated by reference in their entirety for all purposes.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a white light-emitting diode with high uniformity and wide angle intensity distribution, and particularly relates to a color temperature tunable white light-emitting diode with high uniformity and wide angle intensity distribution.[0004]2. Description of the Prior Art[0005]Now, the white LED is fabricated by adhering a yellow phosphor (or a green phosphor or a red phosphor) on a light emitting surface of a blue LED. FIG. 1 shows a conventional white LED 10. The white LED 10 is composed of a LED (such as a blue LED) 14, a lead frame 16, a sealant 12 formed by mixing a phosphor (such as yellow phosphor, green phosphor, or red phosphor) with a glue, and a lampshade 18. The LED 14 i...

AI Technical Summary

Benefits of technology

[0011]In view of the foregoing, one object of the present invention is to provide a white light-emitting diode with high uniformity and wide angle intensity distribution for overcoming above-mentioned shortcomings to provide a stable white light with big illumination area, uniform intensity and color temperature, and good illuminance. Further, the color temperature of the white light generated by the white light-emitting diode can be adjusted.

[0012]According to one of the objects above, a white light-emitting diode with high uniformity and wide angle intensity distribution is disclosed herein. The white light-emitting diode with high uniformity and wide angle intensity distribution comprises a base, a UV LED array, a lampshade, and a white light phosphor layer wherein the UV LED array is deposed on the base, the lampshade is integrated with the base to form a space inside the combination of the lampshade for covering and holding (or containing) the UV LED array therein, and the white light phosphor layer is coated on one surface of the lampshade. The white light phosphor layer is formed by coating a nano-phosphor material on the surface of the lampshade. The white light phosphor layer (or the nano-phosphor material) can be excited by a UV light to form many pointolites (or point light sources) arranged on the surface of the lampshade. Therefore, the white light-emitting diode can provide a stable white light with big illumination area, uniform intensity and color temperature, and good illuminance. Furthermore, the UV LED array comprises two set of UV LEDs, which emit UV lights having different wavelengths respectively, for controlling or adjusting color temperature of the white light-emitting diode. Or, the color temperature of the white light-emitting diode can be adjusted by changing the ratio of compositions of white light phosphor layer.

[0013]Therefore, the present invention provides a white light-emitting diode with high uniformity and wide angle intensity distribution. In the white light-emitting diode, there are many pointolites (or point light sources) formed on the lampshade by the white light phosphor layer, which is formed by coating the nano-phosphor material on the surface of the lampshade, when a UV light illuminates the white light phosphor layer. Therefore, the white light-emitting diode can provide a stable white light with big illumination area, uniform intensity and color temperature, and good illuminance. Further, the color temperature of the white light generated by the white light-emitting diode can be adjusted by different combinations of the UV LEDs respectively having different wavelengths, and different ratio of compositions of white light phosphor layer.

Problems solved by technology

It results in non-uniform intensity of the white light emitted from the conventional white LED 10 at different angles.

It is because the phosphor film is not thin enough to prevent the phosphor film from absorbing the white light generated by the conventional white LED 10.

Besides, it is difficult to precisely control the thickness of the phosphor film to form the phosphor film having a special or predetermined thickness, such as the thickness is thin enough to prevent the phosphor film from absorbing the white light generated by the conventional white LED 10, because most of phosphors used in the conventional white LED 10 have bigger size than micro-scale.

It results in non-uniform color temperature of the white light at different angles.

The temperature rising of the phosphor results in destruction or invalidation of the phosphor.

Therefore, the illumination area of the conventional white LED 10 is not wide enough to provide an all-dememtional illumination or a 360 degree illumination.

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